Preface: I ripped this entire thing off of an Extreme overclocking thread and haven't tried this personally "Beware" and do your own research.. Sorry if this has already been posted to death here already.
Shadowmage says:
Guide to getting the most out of your AMD64 laptop!
For this guide, I'm assuming the following things:
1. You have a laptop with an AMD64 processor. It does not matter if the processor is a DTR, a 62W Mobile, or a 35W Mobile. Note that for the purposes of this guide, I will be using a 62W Mobile CG Revision AMD64 3200+ in my SiS755 chipset IBUYPOWER laptop.
2. You want to get the best battery-life/performance ratio possible.
3. (optional) You are trying to decide between an AMD64 laptop and a Intel Centrino Dothan laptop.
OK, let's get started!
For this guide, you will need the following things:
1. An AMD64 laptop (duh!)
2. Prime95 for stability testing purposes (http://www.mersenne.org/freesoft.htm)
3. CrystalCPUID for multiplier/voltage tweaks (http://crystalmark.info/download/CrystalCPUID36.zip)
4. SiSoft Sandra for confirmation (http://www.sisoftware.net/)
5. Wattage calculation (http://www.benchtest.com/calc.html)
OK, let's get started!!!
Prelim info:
We know that the laptop CPUs with the longest battery life are the Intel Dothan (700s) series. Anandtech has proved that the 755 (2.0ghz) and the 745 (1.8ghz) are very formidable foes, providing excellent power compared to the AMD64 Mobile line (especially the 3000+ and 2800+) at little battery expense (21W compared to 62W).
However, the AMD64 has another trick up its sleeve: PowerNOW! technology. This supports on-the-fly changing of processor speeds and voltage, ranging from (1.4v at full power, to 0.8v at a puny 800mhz for basic tasks and idling). This alone offers a nice boost to battery power. For advanced users, this is especially great due to the fact that they can abuse this through multiplier/voltage changing programs! Note that this is NOT POSSIBLE with the Intel Dothan line.
For this guide, we will be altering the voltage and multiplier settings to provide the optimum performance levels while offering minimal wattage, even rivaling or SURPASSING that of the Intel Dothan line!
Step 1: Turn off PowerNOW! technology.
Go to the control panel, go to "Power Options", and select "Max Battery" from the list of preset profiles. You may change the monitor, hard drive, and standby options to whatever you wish; that part doesn't matter.
Step 2: Start running Prime95
Download Prime95, install it, and run it. Go to "Options", then "Torture test...". Select "In Place Large FFTs", and hit "OK". This will ensure that the computer is stable while you overclock via software.
IF AT ANY TIME PRIME95 FAILS WHEN TWEAKING, IMMEDIATELY FORCE THE COMPUTER TO SHUT DOWN!
Step 3: Run CrystalCPUID
Unzip the zip file, and run the program. Go to "function", "AMD K7/K8 Multiplier", or hit Ctrl + K. Then, check the "show confirmed dialog" for extra security, and then click on "Enable Change Voltage" to enable voltage tweaks.
REMEMBER: ALWAYS INCREASE VOLTAGE BEFORE INCREASING THE MULTIPLIER. ALWAYS DECREASE THE MULTIPLIER BEFORE DECREASING THE VOLTAGE!
Now, we are going to find some key info!
Set the voltage to 1.400v, and the multiplier to 10x. Every minute or so, lower the voltage by 0.025. As soon as Prime95 fails, IMMEDIATELY SHUT DOWN THE COMPUTER! After rebooting, run Prime95 for an hour or so to verify the lowest voltage setting. For my AMD64 3200+ M, the lowest voltage I got was 1.250v, for a total of 50W. That's 12W of saved power for NO LOSS IN PERFORMANCE! Note that all processors are different.
Repeat this for the 4x multiplier settings. It should be easy to accomplish the 0.800v, as I did. I even managed to set the multiplier at 4.5x with the lowest 0.800v setting! This will get you a 900mhz processor that uses a negligible 9W power! I managed to get 0.850v at 5.5x, which is a 1.1ghz @ 13W. Compare this to the UL Voltage Dothan 1.1ghz @ 5W. Although the AMD64 uses more than 100% more power, that's still pretty darn close.
Now, let's find the target 21W frequency. I achieved this at 7x5 at 1.000v. This will get a 1.5ghz @ 24W processor. That's equal to a Centrino 715. 1.7ghz will get me a 31W processor. 1.9ghz gets 41W.
Find the frequencies and the wattage that will yield what you want. Create a few shortcuts and put them on the desktop. I suggest putting the nominal wattage shortcut in the Startup folder. Select the max performance shortcut when playing games, etc.
This is the sole advantage the AMD64 has over the Dothan, besides the 64bit capabilities. It's versatileness is unmatched.
Another good thing about A64 is the insanely cheap price compared to the Dothan!
AMD3200M costs $213 from Newegg.com
Dothan 755, which is same performance, costs $639.
Dothan 715, same performance and battery length as underclocked AMD3200, costs around the same as the AMD3200M.
The ULV 732, I don't know how much that costs, no doubt around $400 or more.
Please post your results here.